There are 2 grams remain
<h3>Further explanation</h3>
Given
t1/2 = 30 years
t = 170 years
No = 100 g
Required
Remaining sample
Solution
General formulas used in decay:
Input the value :
Answer:
using bond energies = - 37 kJ
using enthalpies of formation = - 45.7 kJ
Explanation:
From the reaction;
CH2═CH2(g) + H2O(g) -------> CH3CH2OH(g)
From the above reaction; there are 4 (C-H) bonds , 1 ( C=C) and 2 (H-O) of ethene which forms 5(C-H) bonds, 1 (C-C) and 1 (C-O) and 1(H-O) bonds.
Using Bond Energies; the heat of the reaction can be written as:
∑ energy of old bond breaking + ∑ energies of the new bond formation.
∑ ![[(4 * BE_{C-H}) + BE_{C-C}) + + BE_{O-H})]](https://tex.z-dn.net/?f=%5B%284%20%2A%20BE_%7BC-H%7D%29%20%20%2B%20BE_%7BC-C%7D%29%20%2B%20%20%2B%20BE_%7BO-H%7D%29%5D)
+ ∑ ![[(5 * BE_{C-H}) + BE_{C-C}) + BE_{O-H}+ BE_{C-O})]](https://tex.z-dn.net/?f=%5B%285%20%2A%20BE_%7BC-H%7D%29%20%2B%20BE_%7BC-C%7D%29%20%2B%20BE_%7BO-H%7D%2B%20BE_%7BC-O%7D%29%5D)
∑![[4*413 kJ)+(614kJ)+(2*647kJ]](https://tex.z-dn.net/?f=%5B4%2A413%20kJ%29%2B%28614kJ%29%2B%282%2A647kJ%5D)
+ ∑ ![(5*-413kJ)+(-347kJ)+(-467kJ)+(-358kJ)]](https://tex.z-dn.net/?f=%285%2A-413kJ%29%2B%28-347kJ%29%2B%28-467kJ%29%2B%28-358kJ%29%5D)
-37 kJ
To calculate the heats of reaction by using enthalpies of formation; we have:
∑ 
- ∑ 
∑ 
- ∑ 
(-235.1 kJ) - [(+52.47 kJ) + (-241.826 kJ)]
-45.7 kJ
You don't "turn" it into energy; petroleum HAS stored energy (chemical energy).However, you can turn it into ANOTHER TYPE OF ENERGY; usually this is done by burning the petroleum, and using it to drive machinery.
Since burning fuels is wasteful (the efficiency is limited, in theory, to the Carnot efficiency of a heat engine), other options are being explored, such as chemical reactions in a fuel cell. But such technology is not yet used on a large scale.
If my memory serves me well, the following element which has the most properties in common with iron (Fe) is definitely <span>Osmium (Os) because they are stand for the same group!
I'm sure it helps!</span>
Answer:
The pH of the substance is 4,06.
Explanation:
The pH indicates the acidity or basicity of a substance. PH values between 0 and less than 7 indicate acidic solutions, 7 neutral and greater than 7 to 14 basic. It is calculated as:
pH = -log (H +)
pH= -log (8.8x10^-5)
<em>pH=4,06</em>
